Submission #670217

#	Time	Username	Problem	Language	Result	Execution time	Memory
670217		NothingXD	Palindromes (APIO14_palindrome)	C++14	8 / 100	1105 ms	131072 KiB

palindrome

#include<bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
/*typedef __uint128_t L;
struct FastMod {
  ull b, m;
  FastMod(ull b) : b(b), m(ull((L(1) << 64) / b)) {}
  ull reduce(ull a) {
    ull q = (ull)((L(m) * a) >> 64);
    ull r = a - q * b; // can be proven that 0 <= r < 2*b
    return r >= b ? r - b : r;
  }
};
FastMod FM(2);*/
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

void debug_out() { cerr << endl; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
	cerr << " " << H;
	debug_out(T...);
}

#define debug(...) cerr << "(" << #__VA_ARGS__ << "):", debug_out(__VA_ARGS__)
#define all(x) x.begin(), x.end()
#define MP(x, y) make_pair(x, y)
#define F first
#define S second

//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

map<string,int> mp;

int main(){
	ios_base::sync_with_stdio(false); cin.tie(0);

	string s; cin >> s;

	for (int i = 0; i < s.size(); i++){
		for (int j = i; j < s.size(); j++){
			string t = s.substr(i, j-i+1);
			mp[t]++;
		}
	}

	int ans = 0;

	for (auto [x, y]: mp){
		string t = x;
		reverse(all(t));
		if (t == x) ans = max(ans, y * (int)t.size());
	}

	cout << ans << '\n';

	return 0;
}

Compilation message (stderr)

palindrome.cpp: In function 'int main()':
palindrome.cpp:44:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   44 |  for (int i = 0; i < s.size(); i++){
      |                  ~~^~~~~~~~~~
palindrome.cpp:45:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   45 |   for (int j = i; j < s.size(); j++){
      |                   ~~^~~~~~~~~~
palindrome.cpp:53:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   53 |  for (auto [x, y]: mp){
      |            ^

• Subtask 1: 8 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 24
• Subtask 4: 0 / 26
• Subtask 5: 0 / 27